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Over ten grand on a GTN-650

Many GNS430 installations already have WAAS capable antennas – and cables. Many times only the cables are not good enough and have to be changed. I boutht one new GA-36 antenna and one combined COM-GPS-WAAS antenna, because there was simply not enough room anymore for another antenna…. but that was it. To install the lomger cable for the combined antenna we had to take off the glareshield and tale out the MFD but the rest was pretty straightworward. The unit itself is a slide-in replacement.

Of course all this depends on what is already in the airplane.

Oh, I see.

But any “original” GNSx30 installations will require a new cable and aerial, which is supplied with the upgrade. That does need to be factored in, though it’s not a huge deal.

EGKB Biggin Hill

So if you then take these 20 instrument approaches per year, let’s say maybe 5 of them are in IMC. In these 5 cases, there will likely be 3 airports which do have an ILS. So there is a total of maybe 2 “required” GPS approaches. I deem it very unlikely that in there two cases, the weather will be below LNAV minima (usually about 400 feet), but above LPV minima (usually 250 feet). THAT however would be the only “real” utility aspect of WAAS. All else is IMHO just “gadgeteritis”, or possibly a little bit of convenience (not having to calculate a glidepath, but just lazily following the needle).

That sums it up quite well :-). Its a good exercise to check distance altitude from the MAP in various wind conditions and configurations on an LNAV APP. I can manipulate all functions of the KLN90B quite well. The safety gain versus investment would be much higher with an active TAS system IMHO. My nervous level goes higher when ATC calls you to inform them back when VMC so he can cancel IFR and swipe you off the radar screen asap and dump you on info freq in OCAS with no traffic advisory while your doing 190Kts. When the weather is typical Belgian or UK with a ceiling and lower clouds decks in the weekend and lots of VFR traffic around….btw 1000 and 4000 feet…
If I would retrofit WAAS plus TAS ADS-B in/out thats a 22K investment at least!!!! A simpler lynx 9000+without the additional goodies not needed in Europe…would be a real game changer. Mode S ES and TAS + ADS-B in one unit capable of transmitting over ARINC429/735

Last Edited by Vref at 08 Sep 09:46
EBST

Vref wrote:

Its a good exercise to check distance altitude from the MAP in various wind conditions and configurations on an LNAV APP.

You can do better than that.

All these boxes have a groundspeed readout. It is a Euclidean certainty that if you descend at an accurate RoD appropriate to the groundspeed, you will achieve a particular slope. (Although a 3° slope is actually 318’ per nm, it is much easier to call it 300’ and accept the small error (all part of LNAV DAs being relatively high.))

So it is very easy to look at your exact GS from the GNSS Navigator, halve it and add a zero (so, if you are doing 90 kts groundspeed, halve it to 45 and add a zero to 450fpm) and make that your RoD.

If you do that really accurately, it is just as good as a Glidepath. The check altitudes just come and go bang on target. The only thing is that you have to start at precisely the FAF, not some muddle 30 seconds later!

I have demonstrated this time and time again to students. They actually fly a better glidepath (SBAS or ILS) on pure RoD than they do when they can see the needle!

Last Edited by Timothy at 08 Sep 11:06
EGKB Biggin Hill

boscomantico wrote:

And after spending these 10k, he would still have a very old piece of hardware in his cockpit.

Like many, I have delayed going WAAS for now. If one of my 430s packs up, then it’s a no-brainer.

I upgraded my 430 to 430W, cost was approximately 3000 Euros all in 3 years ago. It was done to make it possible to do LPV and all this but it was also a very good idea for the normal use of the 430 as a navigator.

The W unit is MUCH faster in use, has loads more memory for user waypoints and routes and has quite a few additional features the old 430 doesn’t have. I would not want to go back to the old unit, even though my IR is still on the to do list. If I had a normal 430 in my panel today, upgrading it or them would be very high on my list after flying with a W.

LSZH(work) LSZF (GA base), Switzerland

I upgraded my 430 to 430W, cost was approximately 3000 Euros

What is the approximate breakdown of these 3000 Euros, amongst:
-buying W unit
-selling non-W unit
-new antenna
-new cables
-labour
-paperwork ?

Sounds almost impossible, unless you made very extraordinary deals on the first two items…

Last Edited by boscomantico at 08 Sep 13:10
Mainz (EDFZ) & Egelsbach (EDFE), Germany

You can do better than that.

Sure its on the map also: LFAV LNAV

Still cross check btw the FAF and Mins that this eucledian certainty is shown on the instruments depending on the speed you fly. I prefer to fly flapless, gear down during an LNAV APP with the bonanza to keep things stable as long as possible

Last Edited by Vref at 08 Sep 13:14
EBST

I upgraded my 430 to 430W, cost was approximately 3000 Euros

The cheapest if you have to come from a KLN94/90/89 is to go with a 400W unit which will cost you 5K euro, plus install +paperwork ..IMHO..your looking at 6-7K minimum

EBST

Something else to consider if installing a W box in place of an old (probably non W) box is that you “will” want to get GPSS a.k.a. roll steering. This enables the automatic flight of stuff like holding patterns, DME arcs and other stuff which is in the W box database. But if your autopilot is anything older than say a KFC225, the autopilot won’t take the ARINC429 roll steering data stream from the GPS and you will need to install a roll steering converter. That is probably another 2k or so especially since it will require good wiring access to certain places. In most cases, this will apply even if going from a 430 to a 430W since the vast majority of 430s were installed in the most basic way possible so even though the 430 outputs ARINC429 roll steering, most installers didn’t make use of it. This new functionality needs careful thought if you have a mechanical HSI because the ARINC429 roll steering bypasses the course pointer on the HSI (which is what used to set the rough autopilot heading to fly) so now you have a piece of dead functionality in the panel… It is easier with an EHSI like the SN3500 but even there most installers didn’t connect up the roll steering option which is an extra $1000 software key (and requires firmware v3.5 or higher). The SN3500 roll steering option is really slick since the autopilot knows no difference between ILS and LPV which is really neat.

Administrator
Shoreham EGKA, United Kingdom

Peter; my set up with a SN3500 and KLN90B it anticipates the turn mode as the KLN90B is connected over the ARINC bus, not having GPSS is not real big deal is it?
Till now i didn’t notice a real overshoot even when intercepting angle was relatively steep.in APP mode coupled (1NM).How many times you use this automatic holding in European context apart from training…..?

EBST
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